Microbialite fields emerge as Türkiye's biggest lake declines
Microbialites emerge along the shores of Van Lake as water levels decline in Bitlis, Türkiye, Oct. 22, 2024. (DHA Photo)


As the water level of Lake Van decreases, the shores of Tatvan, Ahlat and Adilcevaz districts in Bitlis, in eastern Türkiye, have turned into a microbialite field. Professor Necmettin Elmastaş, the Rector of Bitlis Eren University (BEÜ), stated that in recent years, a decrease in water levels, particularly in lakes, has been observed due to global warming, resulting in microbialites becoming increasingly common along the shores of Lake Van.

Lake Van, which is the largest soda lake in the world and the largest lake in Türkiye, continues to lose area due to drought associated with global climate change. Despite receiving more rainfall last year compared to previous years, the water level in Lake Van did not reach the desired level.

As the lake water recedes, the microbialites at the lake's bottom are becoming visible. Microbialites, commonly found in areas with freshwater springs, have become more visible on the shores due to recent water withdrawals.

Previously seen densely on the shores of Adilcevaz, microbialites have also begun to appear in Ahlat and Tatvan districts; the shores of İncekaya village in Tatvan have essentially turned into a microbialite field.

Professor Elmastaş further explained that a decrease in rainfall has also been observed over the past four years. Although rainfall amounts may increase in 2024, there is generally a decline in levels. Several factors contribute to this decrease, with rainfall being the primary one.

Looking at the data from the rainfall stations in the Lake Van basin, it is evident that below-average rainfall has been recorded in recent years, therefore, this is the most important reason. Another factor can be the water used for agricultural irrigation. There is a significant agricultural basin extending from Tatvan, Ahlat and Adilcevaz toward Erciş.

In recent years, there has been considerable water consumption in these areas, utilizing thousands of groundwater sources through drilling. This water consumption significantly affects the sources that feed the lake. Some sources have dried up due to the decrease in groundwater levels. Thus, these two fundamental factors have led to a decline in the lake's level.

The decrease in the water level of Lake Van has also revealed some interesting sights, particularly the emergence of microbialites in certain areas, especially around Adilcevaz.